Linux : The Matrix

There are tons of linux command line cheatsheet or guides.

Here are some of the best reads, I suggest you to go throught each of it, It's a gem.

• The Art of Command Line — notes and tips on using the command-line, suitable for both beginners and experienced users.
• commandlinefu — command-line gems, includes a handy search feature.
• tldr — collection of community-maintained help pages for command-line tools.
• explainshell — write down a command-line to see the help text that matches each argument.
• General purpose command-line tools — examples for most common usecases.
• Bash reference cheatsheet — nicely formatted and explained well.
• Bash scripting cheatsheet — quick reference to getting started with Bash scripting.